Dies under load

Well I thought I had fixed the fuel problem, new tank, new pickup, new fuel pump, replace flexible lines, flush out hard lines, had carburetor rebuild , new fuel filter.

I was having an issue with blow back when trying to start, stuck float, that’s why I had the carburetor rebuild a second time

Truck starts and runs at idle. Start to move, give it a bit of gas and let off the clutch, goes fine for about 200 feet, and then it dies. Coast to a stop. Pump accelerator and it starts right back up, and repeat.

Check timing right on 8deg, vacuum line disconnect. Then a funny thing happens, the timing mark goes away, comes back, goes away, comes back.

Cannot hear any change in rpm’s. Guess I’m going to have to get a new tack.

Any one with a possible cause?

Could the DSII be going bad?

Usually if a DursSpark module starts to fail it will die when hot and come back 30+ minutes later once it cools down.

That hasn't been my experience.
I'm driving along and I get a single backfire, when the module dies.

But if you seem to have intermittent spark (at least on #1 where the timing light is connected) grab a hold of the ignition coil and see if it is scorching hot.

Yes it’s hot, almost too hot to touch

Your coil shouldn't get that hot, that fast.
Unless you leave the ignition on and the engine not running.

Check to see if the resistor is functional.
Disconnect both the coil horseshoe and the dura spark power plug.
On between the (red) hot wire of the coil and both the red and the white wire of the dura spark.

How many ohms do you find at each connection?.

I'm using the Standard Automotive Products Blue streak coil.FD-476



Get the better of the two.
The one without the (T) suffix.
I think it's T, for tech grade. But it's no good.

I did have a DSII act like a choke issue that drove me nuts
Start the car let it run a bit to warm up, 5 to 10 min.
Could drop it into gear and drive down the street and stop for a light and it would stall.
Same coming home from work, let warm up may be under 5 min, pull out of theparking lot, had to wait for gate to open, then a short distance to the light and it would stall.

Each time it would start right back up and be ok for the rest of the trip of about 5 miles.
This was on the wife's car and when ever drove it it would run find and never stall. \
But I kept adjusting the choke because of the stalling.
Talking to a buddy of mine he said to change out the DSII box and never an issue after that.

I say change out the box and see what happens and if it still does the same thing you now have a spare.
I have also had them heat up and stop the motor like the key was turned off. Sometimes just opening the hood was enough to cool it down and it would start back up.

When running have you tried moving the wires going to the box and the dist. to see if that dose anything?
The other thing to try is remove the vacuum hose to the vacuum advance on the dist. and plug it and see if it has the issue.

Oh you said you have a tach what happen to it when the motor stops, dose it just go to 0 RPM or bounce a little before? I had another car that would shut down but the tach would jump a little just before it would die. Moving the wires did nothing, replacing the box did nothing I think what may have been the cause was the pick up coil inside the dist.
I say "think" as I had to move the car and I had a RTR Mallory dist. I pulled from my race car that I dropped in. I did replace the pick up coil in the dist but being lazy I never swapped the dist. back into the motor so not 100% sure of the fix.

Keep us posted on what you fine.
Dave ----

So Dave, what do you have to say about the sorching hot coil?

To me, that's very telling.
And it's not pointing at the rest of the ignition system.

ArdWrknTrk wrote

So Dave, what do you have to say about the sorching hot coil?

To me, that's very telling.
And it's not pointing at the rest of the ignition system.

DON'T TOUCH IT

I never had one that ran hot so I never had to deal with that.
Also all the cars I had the issues on were factory stock, no one swapped out parts like installing the wrong coil.

So if the coil is getting hot I think I would check if it is the right one.
How is it mounted? If oil filled they need to be mounted a certain way as the oil keeps them cool.
What is the voltage going to it?
If all else fails replace it
Dave ----

I already pointed out how to check for the resistor in run.

The part # I offered is known good, by running almost a decade in my DSII truck.

If the coil is shorted out it's hard to go wrong for a $15 plug & play part.

But obviously our experience with DSII modules differs.
I don't know what to say about that, except the OP hasn't mentioned module potting running down the inner fender.

ArdWrknTrk wrote

I already pointed out how to check for the resistor in run.

The part # I offered is known good, by running almost a decade in my DSII truck.

If the coil is shorted out it's hard to go wrong for a $15 plug & play part.

But obviously our experience with DSII modules differs.
I don't know what to say about that, except the OP hasn't mentioned module potting running down the inner fender.

I have potting running down the inner fender on my truck and it runs just fine.
I should pull the other from my parts fender and throw it in the truck just in case LOL

The others I had go bad, 76 AMC with a 258 six, 78 Merc with a 300? six, and neither leaked potting.
Dave ----

I'm just saying you know the transistor in the module is getting way too hot if it melted the potting out.

I'm not sure that it would have failed at that point, but it is definitely above proper service temperature.

On the 12th when I asked the question, I had been messing with the truck most of the morning. Killing the battery by repeatedly restarting.

I have no idea of how old the coil is, the pickup inside the distributor was replaced 3 years ago, and the plug wires cap and rotor last year. Looking at the DSII I could not see anything running out of it. I did wiggle the wires all the way from the DS to the distributor. There was no change. I had not thought of a resistor but I will check it out. I have a new timing chain and water pump setting in the garage, just have higher priorities,

I ordered a new coil just because. Hopefully I will be able to get back to it today. Weather is supposed to be good.

New coil arrived today, put it on made no difference. So pulled the top off the carburetor. Float bowl was dry,  I pulled the float and needle valve out. There was a piece of Teflon tape stuck around the needle valve. Turn the motor over a few times and more pumped out. Put the carburetor back together and it runs like it’s supposed to.

Anyway it has a new fuel filter, new coil, DSII, and tach. Hopefully nothing else goes wrong for a while. We’re getting ready to start planting so I will not have time for a while.

But as of this afternoon it’s good.

Thanks for the help.

. Tef tape has no place in a fuel system.
Everything should be flare fittings, except the fuel filter to carb, and that gets a sealing washer.

Wow! I'm glad you found it.  
That trouble is over, but unfortunately something else will come along.

Well, you've solved one problem and probably prevented several other.